A toner for developing an electrostatic image to be used for a heat fixing method is required to be not fuse with a heat roll even at a high fixing temperature (hot offset resistance); fixed even at a low fixing temperature (low temperature fixing property); and good in the grindability of a resin thereof used in producing the toner. Generally the low temperature fixing property and the grindability of the resin at the time of toner production tend to be mutually contradictory properties. As a toner excellent in the low temperature fixing property and good in the grindability of the resin at the time of toner production is disclosed a toner containing a resin for a toner containing a specified amount of a monovalent aliphatic compound having 10 to 24 carbon atoms as a monomer component (reference to Patent Document No. 1).
Also, as an attempt to provide a toner that satisfies the low temperature fixing property and is free from high temperature offset, a toner having a loss tangent (tan δ) in a range from 1.0 or higher and lower than 2.0 in the case the loss modulus G″ is in a range from 1×104 Pa to 1×106 Pa, and a loss tangent (tan δ) in a range from 0.5 or higher and lower than 1.0 in the case the loss modulus G″ is 1×103 Pa is disclosed (reference to Patent Document No. 2).
However, although the toner proposed in Patent Document No. 1 is excellent in the low temperature fixing property, it is required to be improved in both low temperature fixing property and grindability for speed up and saving energy. Also, the toner proposed in Patent Document No. 2 is good in the low temperature fixing property and high temperature offset properties, however it is insufficient to give satisfactory image quality for the use of color images required to have luster.
To improve the moisture resistance and fixing capability of a polyester toner, it is known that long chain aliphatic hydrocarbon units are introduced into the main chains or side chains of polyester resins by co-condensing tri- or higher valent polyhydric alcohols with long chain aliphatic dicarboxylic acids or dicarboxylic acids having long chain aliphatic side chains (reference to Patent Document No. 3).
However, in these polyester resins, since sebacic acid or the like is used as a long chain aliphatic dicarboxylic acid and dodecenylsuccinic acid or the like as a dicarboxylic acid having a long chain aliphatic side chain is used, the number of carbon atoms of the aliphatic hydrocarbon unit to be introduced become so high and although the moisture resistance and fixing property of a toner are improved, the glass transition temperature (Tg) of the polyester resins is lowered to lead to a problem that the storage stability of a toner is deteriorated.
A toner for electrostatic image development to be used for a heat fixing method is required to be not fuse with a heat roll even at a high fixing temperature (hot offset resistance) and fixed even at a low fixing temperature (low temperature fixing property). To prevent hot offset, use of a wax is effective and to improve the low temperature fixing property, it is effective to use a polyester type resin as a binder for a toner.
However, compatibility of a wax and a polyester type resin is poor and the dispersion particle diameter of the wax becomes large in a toner. Accordingly, it results in fixing or filming of the wax on a photoconductor to deteriorate image quality or charging failure to deteriorate image quality. To solve these problems, Patent Document No. 4 proposes use of graft polymers having a graft structure formed by grafting styrene type polymer chains or styrene-(meth)acrylic polymer chains to wax components. Accordingly, the wax particle diameter in a toner is made controllable and toners which are excellent in hot offset resistance and do not cause filming or image deterioration are proposed.
However, the toners proposed in the Document are insufficient from a viewpoint of the low temperature fixing property although being effective in the hot offset resistance and causing no filming or image deterioration.
As particles having uniform particle diameter and shape and excellent in the electric property, thermal property, and chemical stability have been known resin particles obtained by a suspension method of removing organic solvents from suspensions of water-based media and mixed solutions containing resins and the organic solvents (reference to Patent Document No. 5).
However, with respect to resin particles to be used for heat fixing method/heat processing method, they are further required to be suitable for fixing and melting even at a low temperature from a viewpoint of saving energy and the resin particles described in Patent Document No. 5 are not necessarily sufficient as resins for slush molding, a powder coating, an electrophotographic toner, an electrostatic recording toner, an electrostatic printing toner, or hot-melt adhesive.    Patent Document No. 1: Japanese Patent Laid-Open (JP-A) No. 2003-337443    Patent Document No. 2: JP-A No. 2003-280241    Patent Document No. 3: JP-A No. 62-78568    Patent Document No. 4: JP-A No. 2001-134009    Patent Document No. 5: JP-A No. 2001-166538